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排序方式: 共有246条查询结果,搜索用时 17 毫秒
161.
Psotova J Svobodova A Kolarova H Walterova D 《Journal of photochemistry and photobiology. B, Biology》2006,84(3):167-174
UVA radiation provokes the generation of reactive oxygen species (ROS), which induce oxidative stress in the exposed cells leading to extensive cellular damage and cell death either by apoptosis or necrosis. One approach to protecting human skin against the harmful effects of UV radiation is by using herbal compounds as photoprotectants. This study evaluated the protective effects of Prunella vulgaris L. (Labiatae) and its main phenolic acid component, rosmarinic acid (RA), against UVA-induced changes in a human keratinocyte cell line (HaCaT). Human keratinocytes exposed to UVA (10-30 J/cm(2)) were treated with an extract of P. vulgaris (1-75 mg/l) or RA (0.9-18 mg/l) for 4h. P. vulgaris and RA exhibited ability to reduce the UVA-caused decrease in a cell viability monitored by neutral red retention and by LDH release into medium. The P. vulgaris extract and RA significantly suppressed UVA-induced ROS production, which manifests as a decrease in intracellular lipid peroxidation, elevation of ATP and reduced glutathione. Post-treatment with P. vulgaris extract and RA also significantly reduced DNA damage. In addition, UVA-induced activation of caspase-3 was inhibited by treatment with P. vulgaris and RA. The P. vulgaris extract and RA demonstrated a concentration-dependent photoprotection (maximum at 25-50 mg/l and 9 mg/l, respectively). These results suggest that P. vulgaris and RA, used in skin care cosmetics, may offer protection against UVA-induced oxidative stress and may be beneficial as a supplement in photoprotective dermatological preparations. 相似文献
162.
Lukas Englert Andreas Stoy Dr. Merle Arrowsmith Dr. Jonas H. Muessig Melanie Thaler Andrea Deißenberger Alena Häfner Dr. Julian Böhnke Dr. Florian Hupp Dr. Jens Seufert Dr. Jan Mies Dr. Alexander Damme Dr. Theresa Dellermann Kai Hammond Dr. Thomas Kupfer Dr. Krzysztof Radacki Torsten Thiess Prof. Dr. Holger Braunschweig 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(36):8612-8622
A series of 22 new bis(phosphine), bis(carbene), and bis(isonitrile) tetrahalodiborane adducts has been synthesized, either by direct adduct formation with highly sensitive B2X4 precursors (X=Cl, Br, I) or by ligand exchange at stable B2X4(SMe2)2 precursors (X=Cl, Br) with labile dimethylsulfide ligands. The isolated compounds have been fully characterized using NMR spectroscopy, elemental analysis, and, for 20 of these compounds, single-crystal X-ray diffraction, revealing an unexpected variation in the bonding motifs. In addition to the classical B2X4L2 diborane(4) bis-adducts, certain more sterically demanding carbene ligands induce a halide displacement which led to the first halide-bridged monocationic diboron species, [B2X3L2]A (A=BCl4, Br, I). Furthermore, low-temperature 1:1 reactions of B2Cl4 with sterically demanding N-heterocyclic carbenes led to the formation of kinetically unstable mono-adducts, one of which was structurally characterized. A comparison of the NMR spectra and structural data of new and literature-known bis-adducts shows several trends pertaining to the nature of the halides and the stereoelectronic properties of the Lewis bases employed. 相似文献
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Ludmila Klukova Tomas Bertok Miroslava Petrikova Alena Sediva Danica Mislovicova Jaroslav Katrlik Alica Vikartovska Jaroslav Filip Peter Kasak Anita Andicsová-Eckstein Jaroslav Mosnáček Jozef Lukáč Jozef Rovenský Richard Imrich Jan Tkac 《Analytica chimica acta》2015
Systemic sclerosis (SSc) is an autoimmune disease seriously affecting patient’s quality of life. The heterogeneity of the disease also means that identification and subsequent validation of biomarkers of the disease is quite challenging. A fully validated single biomarker for diagnosis, prognosis, disease activity and assessment of response to therapy is not yet available. The main aim of this study was to apply an alternative assay protocol to the immunoassay-based analysis of this disease by employment of sialic acid recognizing lectin Sambucus nigra agglutinin (SNA) to glycoprofile serum samples. To our best knowledge this is the first study describing direct lectin-based glycoprofiling of serum SSc samples. Three different analytical methods for glycoprofiling of serum samples relying on application of lectins are compared here from a bioanalytical point of view including traditional ELISA-like lectin-based method (ELLA), novel fluorescent lectin microarrays and ultrasensitive impedimetric lectin biosensors. Results obtained by all three bioanalytical methods consistently showed differences in the level of sialic acid present on glycoproteins, when serum from healthy people was compared to the one from patients having SSc. Thus, analysis of sialic acid content in human serum could be of a diagnostic value for future detection of SSc, but further work is needed to enhance selectivity of assays for example by glycoprofiling of a fraction of human serum enriched in antibodies for individual diagnostics. 相似文献
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167.
Lu Wang Zdenk Sofer Daniel Boua David Sedmidubský tpn Huber Stanislava Matjkov Alena Michalcov Martin Pumera 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2016,128(45):14171-14175
Graphane, the hydrogenated counterpart of graphene, was shown to exhibit properties such as tunable band gaps through varied degrees of hydrogenation, fluorescence, or ferromagnetism. Graphane nanostripe properties have also been theoretically predicted. Herein, we show that graphane nanostripes can be prepared by opening carbon nanotubes using Birch reduction in liquid ammonia utilizing potassium as a reducing agent and water as a proton donor. The prepared graphane nanostripes exhibit several exceptional properties when coupled with trace metal dopants. The interplay of metallic nanoparticles and defects lead to a spin polarization and induction of ferromagnetic moment, as well as to enhanced electrocatalytic properties in the hydrogen evolution reaction when compared to non‐hydrogenated carbon nanotubes. 相似文献
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Alexey Bykov Alexander Panin Alena Sharlo 《Mathematical Methods in the Applied Sciences》2017,40(6):1949-1963
An asymptotic expansion of the contrasting structure‐like solution of the generalized Kolmogorov–Petrovskii–Piskunov equation is presented. A generalized maximum principle for the pseudoparabolic equations is developed. This, together with the generalized differential inequalities method, allows to prove the consistence and convergence of the asymptotic series method. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
170.
Olga Maťátková Irena Kolouchová Eva Kvasničková Richard Ježdík Jan Masák Alena Čejková 《Chemical Papers》2017,71(8):1471-1480
Emerging resistance of microbial cells towards antibiotics or disinfectants leads to an increase of nosocomial diseases, often biofilm related, and gives rise to the need for research for new antimicrobial substances. These studies are often focused on substances that are able to support the efficacy of currently used antimicrobials, reduce their required dosage and reduce the probability of resistance development. This work brings new insights into the in vitro interaction of rhamnolipid biosurfactant and amphotericin B against Candida sp. or Trichosporon sp.. The minimum inhibitory concentrations and fractional inhibitory concentration indexes for both planktonic and biofilm cells were determined by the chequerboard microdilution method. Combination effect of rhamnolipid and amphotericin B was observed for both yeasts. Synergy, defined as a fractional inhibitory concentration (FICi) index of 0.50, was observed in both planktonic and biofilm cells of Trichosporon cutaneum. For C. parapsilosis, synergistic effect (FICi 0.5) was observed for planktonic cells, and additive effect (FICi 0.8) for biofilm cells. The influence of concentrations established as FICi on biofilm formation and susceptibility was studied by light microscopy. The highest inhibition (90% colonized area reduction) of initial adhesion of C. parapsilosis was observed when biofilm FIC was applied. 相似文献